How are F-35As different from F-35Bs, and what will the new fighters add to Singapore's defence capabilities?

SINGAPORE: Defence Minister Ng Eng Hen on Wednesday (Feb 28) announced that Singapore will buy eight F-35A jets, bringing the size of the Republic of Singapore Air Force's (RSAF) future F-35 fleet to 20 aircraft. 

Speaking at the Ministry of Defence's (MINDEF) budget debate in parliament, Dr Ng prefaced his speech by acknowledging that the "world has become a more dangerous place", referencing the Russia-Ukraine and Israel-Hamas wars.

He said a strong Singapore Armed Forces acts as a deterrence against aggression and adventurism. 

"If Singaporeans will not, or cannot, defend Singapore, there is no backstop," he said.

The latest purchase comes on top of existing orders for 12 F-35 jets of the B variant from US manufacturer Lockheed Martin. Once all are operational, they will put Singapore's air force in the "premier league", said Dr Ng.

The F-35As are expected to be delivered in around 2030 while the F-35B jets ordered in 2020 and 2023 are projected to arrive in 2026 and 2028 respectively.

Singapore is one of four countries in the Indo-Pacific region to acquire F-35s, along with Australia, Japan and South Korea. Globally, F-35 users apart from the United States include Canada, Israel, the United Kingdom and other European powers.

So what exactly will the F-35As bring to the table? And how are they different from the existing F-35Bs on order? CNA spoke to three defence analysts to find out.

What are the differences between the two planes?

The F-35A can fly further and carry more weapons than the F-35B, and this is tied to differences in how the two fighters operate.

While the F-35B can take off over very short distances and perform vertical landings, the F-35A takes off and lands conventionally.

The F-35B's abilities are valuable. In land-scarce Singapore, the fighters will enhance RSAF's operational flexibility while also boosting the country's resilience against attacks on its runways.

These abilities come at a cost, however. The hardware that enables the F-35B to perform its take-offs and landings takes up space, reducing the amount of fuel and weaponry it can carry.

"The F-35A – the conventional take-off and landing variant, has a higher internal fuel capacity, allowing it to have greater endurance as compared to the B variant," MINDEF said in a fact sheet issued on Thursday.

"Without the need for a lift fan which is present in the F-35B to provide the short take-off and vertical landing capability, the F-35A is able to carry payloads of higher capacity, thereby complementing the F-35B, and providing the RSAF with greater flexibility to meet our operational needs."

The weapons payload for the F-35A is 8,160kg, while the F-35B can carry a payload of 6,800kg.

"The greater payload means being able to carry more air-to-air missiles, larger bombs internally – 2,000-pound (907kg) bombs versus 1,000-pound bombs – and more bombs externally on the wings," said Dr Peter Layton, a visiting fellow at the Griffith Asia Institute.

With 8,278kg of internal fuel capacity, the F-35A has a range of 2,200km. The F-35B, which can carry 6,125kg of fuel internally, has a range of 1,667km.

The F-35A is also cheaper than other F-35 variants because it is "simpler in engineering terms", said Australian Strategic Policy Institute senior analyst Euan Graham.

The Singapore government does not give detailed cost figures for the acquisition of planes, submarines and army platforms as these can provide an indication of capabilities.

But the average price for F-35A jets to be delivered from 2023 to 2025 was reportedly about US$82.5 million (S$111 million), according to a United States government spokesperson.

Additionally, maintenance costs for the two planes differ.

"The F-35B is more complex and costly to maintain and has lower reliability and availability," said Dr Layton.

What is the value of the additional payload capacity and longer range?

With their ability to stay airborne longer while carrying more weapons, the F-35As could serve as reliable sentinels and a line of defence at a distance, said Dr Layton. 

"Given the numbers, the F-35A might have a primary role of being a highly survivable, stealthy 'eye in the sky' that can data-link radar detections of approaching hostile aircraft back to Singaporean ground-based air defence missile systems," said Dr Layton, adding that they would also be able to provide this data to RSAF's F-15SGs.

"The second use of the F-35As might be in an air defence role as a well-forward, combat air patrol barrier relying on stealth to survive to attack approaching hostile aircraft," he continued.

"The F-35A could be a strike aircraft but it has a limited range and payload compared to the F-15SG. Better to use the F-35A clean – with no external stores – so maximising its stealth."

What are the pros and cons of having both aircraft?

In his speech, Dr Ng also said that the F-35As would "complement" the F-35Bs, and analysts that CNA spoke to highlighted this as a key benefit of RSAF having both aircraft variants.

Illustrating this, Dr Graham said that RSAF would be able to continue operating F-35Bs if the runways used by F-35As are "out of action".

Dr Layton, meanwhile, said that the F-35Bs would be "a viable fallback if Singaporean air bases are put out of action for a short time".

Singapore will be one of just a handful of countries operating the two F-35 variants, and this says something about the country's standing, said Dr Cynthia Cook, director of the Defense-Industrial Initiatives Group at the Center for Strategic and International Studies.

"This demonstrates Singapore's status as a highly capable partner," she said.

Dr Cook said that a downside to having the two variants is that maintenance costs could go up.

"There are enough differences between the two aircraft that maintenance personnel may need additional training, and there will be different parts to manage for repair, should the plan be to maintain any of these aircraft domestically," she said. 

Dr Layton agreed, highlighting that the airframes and engines of the two planes are different. However, he noted that there might also be some savings as both F-35 variants have similar electronics and may rely on similar simulators.

How will these planes shape the RSAF of the future?

The F-35 fighters will replace Singapore's ageing fleet of F-16s, which are slated for retirement from the mid-2030s.

The RSAF's future fleet of fighters will made up of F-35As, F-35Bs and F-15SGs. Together, they will be able to perform the "full suite of missions required to defend Singapore's skies", Lieutenant-Colonel Zhang Jianwei, the head of RSAF's Next Generation Fighter Project Office, said at a media briefing on Monday.

The F-15SG jets, which became fully operational in 2013, will do the "heavy lifting" as they can carry even greater payloads, he said.

When asked why it was important for an air force to have a diversified fleet of fighters, Dr Cook said: "They have different missions, different capabilities and different flying hour costs.

"A diverse fleet allows choices."

Dr Graham said the future fleet will be "more diverse compared with the RSAF's current frontline mix of F-16 and F-15 ... ensuring that the RSAF maximises Singapore's very limited depth".

"That will count for more once Paya Lebar is shut down and the RSAF consolidates into Tengah and Changi," he said.

In his speech, Dr Ng said that, with the three fighters, the RSAF of the future "will be a capable air force, above all, to protect (Singapore's) skies".

This article was originally published on ChannelNewsAsia. Its inclusion on this website is solely for education purposes.